Background

Up to 30% of LSG cases require revisional surgery in patients who experience insufficient weight loss (IWL). This study aimed to compare perioperative outcomes and weight changes in patients who underwent either conversion from LSG to Roux-en-Y Gastric Bypass (C-RYGB) or Duodenal Switch (C-DS).

Methods

This study was a nonrandomized, controlled, retrospective review of 73 patients who underwent conversion of LSG due to IWL at our institution from January 2015 to August 2023. Perioperative and postoperative variables were examined.

Results

Of 481 LSGs, 73 patients (63 C-RYGB; 10 C-DS) underwent conversion due to IWL. The average time to conversion was 5 years with a higher preoperative BMI in the C-DS group compared to C-RYGB (56.7 kg/m2 vs 40.0 kg/m2, p<0.001). Additionally, C-DS showed shorter operative time (143.9 min vs 180.1 min, p=0.050) and a similar length of hospitalization than C-RYGB. There was no significant difference in late reoperation rate between groups (8 C-RYGB: 4 internal hernias, 4 cholecystectomies vs 2 C-DS: 1 internal hernia, 1 cholecystectomy). The C-DS group had significant differences in %TWL at 12- (30.3% vs 19.1%, p=0.016) and 24-month follow-up (33.3% vs 18.8%, p=0.017) over C-RYGB (Figure 1). Higher preoperative BMI at the time of conversion was a predictive factor of greater weight loss (each 1 kg/m2 increase yielded 0.7% greater %TWL).

Conclusions

C-DS appears to be safe and feasible for the surgical management of IWL after LSG. In addition, C-DS provides a significantly higher %TWL at 12 and 24 months compared to C-RYGB.